1. Field of the Invention
The present invention relates to data processing apparatus, data processing method, and a storage medium that has stored a program for executing the data processing method.
2. Description of the Related Art
In the technical field of data processing apparatuses, there is growing need to reduce power consumption which the data processing apparatuses unnecessarily consume. One known approach to the need is a technique for reducing power consumption in an inactive state by reducing (or interrupting) power supply to a main control unit controlling a data processing apparatus more than in a normal state, in a state where the data processing apparatus does not operate (inactive state).
Further, the communication function is being embedded in the data processing apparatuses as a standard feature. Such a data processing apparatus can perform various kinds of data processing by receiving data and a command from an information processing apparatus, such as a personal computer, over the network and processing the data and command.
In the data processing apparatus having such a communication function, there is available a technique for reducing a portion of electric power of the data processing apparatus, while maintaining the communication function of the data processing apparatus.
For example, Japanese Patent Application Laid-Open NO. 2009-151537 discussed a technique in which, in a state where power supply to the main control unit is reduced (or interrupted) more than in a normal state, the communication unit, upon receiving a network packet which can be responded to by itself, implements network response without returning the power supply to the main control unit to the normal state.
In a technique discussed in Japanese Patent Application Laid-Open NO. 2009-151537, power-saving is realized by reducing power consumption of the main control unit.
Furthermore, additional power-saving can be realized by reducing power consumption in the communication unit. However, one wants to avoid communication capability from ceasing to be appropriate as a result of having reduced power consumption of the communication unit.
For example, in a case where power-saving of the communication unit has been realize by lowering a communication speed of the communication unit, under an environment in which the communication amount is large, an amount of data which fails to be acquired will be increased.
On the other hand, it is a waste of the power consumption of the communication unit to keep the communication speed of the communication unit high, under an environment in which the communication amount is small.